湄洲湾海域甲藻孢囊的时空分布初步调查

为了解湄洲湾海域表层沉积物中甲藻孢囊的时空分布特征，于2018年5月(春)、8月(夏)、11月(秋)和2019年2月(冬)采集湄洲湾海域7个站位表层沉积物样品，进行甲藻孢囊分析，共鉴定出甲藻孢囊6大类42种和2种未知种。异养型甲藻孢囊种类数和丰度均高于自养型甲藻孢囊，其中又以原多甲藻类孢囊的种类和丰度最高。季节间差异不明显：种类数介于34～38种之间，丰度则在397.8～569.5 cysts/g之间变化，全年平均丰度448.0 cysts/g。工业区附近的站位种类数和丰度均低于养殖区附近的站位和对照点。优势种高达16种，原多甲藻类占绝对优势，但全部优势种优势度均不大。多样性指数、丰富度指数和均匀度指数均较高，全年的平均值分别为3.45、1.55和0.92。与历史资料对比，新发现19种孢囊，但丰度相差不大。另需注意的是，在湄洲湾海域共发现6种有毒甲藻孢囊，虽然全年丰度均不高，但仍有暴发有毒赤潮的危险，需引起重视。

A preliminary investigation of spatial and temporal distribution of dinoflagellate cysts in the Meizhou Bay

To investigate the spatial and temporal distribution of dinoflagellate cysts in surface sediment of Meizhou Bay, surface sediment was sampled at 7 stations in Meizhou Bay in May 2018 (spring), August 2018 (summer), November 2018 (autumn) and February 2019 (winter) for analysis of dinoflagellate cysts. In total, 42 species representing 6 groups, and 2 uncertain taxa were identified. The species number and abundance of heterotrophic species were higher than those of autotrophic species, and among them the species number and abundance of the protoperidinioid group were the highest. Seasonal difference was not obvious: the species number ranged from 34 to 38, and the abundance varied from 397.8 to 569.5 cysts/g with the annual average of 448.0 cysts/g. The species number and abundance of species at stations near the industrial zone were lower than those near the aquaculture area. There were 16 dominant species, among which the protoperidinioid group had an absolute advantage, but the dominance degree of all these dominant species was not large. Diversity index, richness index and evenness index were high, with the annual average of 3.45, 1.55 and 0.92, respectively. Compared with historical data, 19 new cysts were recognized, but the abundance was not much different. It should also be noted that a total of 6 toxic dinoflagellate cysts were found in the waters of the Meizhou Bay. Although the annual abundance was not high, there is still a risk of toxic red tides, which should be taken seriously.